Power measurement circuit

ABSTRACT

A system for power measurement in an electronic device includes a sensing unit, an analog-to-digital converter (ADC) and a controller. The sensing unit senses voltage across a power source and modulates a carrier signal based on the sensed voltage. The ADC converts a combination of the modulated carrier signal and audio signals received by the electronic device to generate a digitized combined signal and provides the digitized combined signal to the controller. The controller separates digitized modulated carrier signal and digitized audio signals. The digitized modulated carrier signal is demodulated to generate an output signal that provides a measure of the power consumed by the electronic device.

RELATED APPLICATIONS

The present application is a divisional U.S. patent application Ser. No.12/842,256, filed Jul. 23, 2010, now U.S. U.S. Pat. No. 8,587,292 whichclaims the benefit of priority Indian Patent Application No.1229/DEL/2010 filed May 28, 2010, both of which are incorporated hereinby reference in their entireties.

TECHNICAL FIELD

The present invention relates to integrated circuit (IC) chips, and moreparticularly, to power measurement in IC chips.

BACKGROUND

With current advancements in technology, IC chips have becomeincreasingly complex and achieve a high level of integration. Today, ICchips are used to perform various functions in electronic devices, suchas mobile phones, cameras, set-top boxes, and personal digitalassistants (PDAs).

The IC chip typically includes a power management system which manages,amongst other things, the power supplied to the IC chip. The powermanagement system further includes a power measurement circuit forestimating the power consumed by the IC chip. The power measurementcircuit estimates the power consumed by the IC chip, by measuring acurrent drawn from a power source.

Power is generally measured by placing a sensor, for example, aresistor, across the power source. The voltage drop across the sensor issensed. The sensed voltage is provided to the power management system inthe IC, for managing the power requirement in the IC chips. However,interfacing of the sensed voltage with the power management system inthe IC chip requires additional components and engages pins of the ICchip, thereby increasing cost and reduced functionalities of theelectronic device.

SUMMARY

This summary is provided to introduce concepts related to powermeasurement in an IC chip, which are further elaborated in the detaileddescription. This summary is not intended to identify essential featuresof the claimed subject matter nor is it intended for use in determiningor limiting the scope of the claimed subject matter.

In an implementation of the present subject matter, voltage drop acrossa power source coupled to an electronic device is sensed. The sensedvoltage is used to modulate a carrier signal. The electronic devicegenerally receives one or more audio signals. The received audio signalsand the modulated carrier signal are combined together and digitized.The digitized combined signal is processed to separate the digitizedmodulated carrier signal from the digitized audio signals. The digitizedmodulated carrier signal is demodulated to generate an output signal,which provides a measure of the power consumed by the electronic device.

These and other features, aspects, and advantages of the present subjectmatter will be better understood with reference to the followingdescription and appended claims. This summary is provided to introduce aselection of concepts. This summary is not intended to identify keyfeatures or essential features of the claimed subject matter, nor is itintended to be used for to limiting the scope of the claimed subjectmatter.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description is provided with reference to the accompanyingfigures. In the figures, the left-most digit(s) of a reference numberidentifies the figure in which the reference number first appears. Thesame numbers are used throughout the drawings to reference like featuresand components. For simplicity and clarity of illustration, elements inthe figures are not necessarily to scale.

FIG. 1 illustrates an exemplary system for power measurement, inaccordance with an embodiment of the present subject matter.

FIG. 2 illustrates an exemplary device having a power measurementcircuit, in accordance with an embodiment of the present subject matter.

FIG. 3 illustrates graphs of signals generated during the powermeasurement, in accordance with an embodiment of the present subjectmatter.

FIG. 4 illustrates an exemplary sensing circuit, in accordance with anembodiment of the present subject matter.

FIG. 5 illustrates an exemplary method for power measurement, inaccordance with an embodiment of the present subject matter.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The disclosed subject matter relates to power measurement in IC chips.Particularly, the subject matter relates to a power measurement circuitof an IC chip that is configured to receive analog audio signals.

Presently, the IC chips used in electronics devices, such as mobilephones, cameras, PDAs, and set-top boxes, are operated using an externalpower supply, for example, a battery. The power consumption within suchelectronics devices varies with the functionalities and the operationsbeing performed using the electronic devices. For example, the powerconsumption in the electronic device would increase with an increase inusage of the electronic device. Similarly, during instances of lowusage, the power consumption would also be low. However, it should benoted that the power within the battery gets depleted during the courseof time.

Generally, a power management system is provided to minimize the powerconsumed in the electronic devices. For example, the power managementsystem may reduce the power requirements of the electronic devicedepending on whether the electronic device is functioning in an idlemode. For the purpose, a measurement of the power consumed from thebattery is desired.

Conventionally, power consumption of an electronic device is estimatedby measuring the current that is drawn from the battery by theelectronic device. For this, voltage across a sensor, for example, aresistor, is sensed. The sensed voltage, which is a direct current (DC)voltage, may be digitized and then provided to the power managementsystem associated with the electronic device. As the resistance of thesensor is known, the power management system can estimate the currentdrawn based on the sensed voltage. This estimate could be used for powermanagement in the electronic device.

The digitization of the sensed voltage for the estimation of the powerbeing consumed can be performed by various ways. The sensed voltage canbe provided to a terminal of a three terminal device, for example, thegate terminal of a transistor. As is known, the current through twoterminals of the transistor is based on the voltage applied at its thirdterminal. Thus, the current through drain and source terminals of thetransistor may vary based on the sensed voltage applied at the gateterminal of the transistor. Such a varying current can be digitized, sayby using an analog-to-digital converter (ADC).

Alternatively, the sensed voltage can be used to drive a voltagecontrolled oscillator (VCO). Depending on the sensed voltage, thefrequency of the signal generated by the VCO varies. The generatedsignal can be provided to a counter to measure the variation in thefrequency and determine the average value of the sensed voltage.However, in both the cases, additional components, such as the ADC, arerequired to provide the measurement of the sensed voltage to the powermanagement system in the electronic device.

Electronic devices, such as mobile phones, may typically receive audiosignals for various functions. For example, in a mobile phone, audiosignals from a user can be received during a mobile phone call. The ADCis generally used for interfacing audio signals with an IC chip of anelectronic device. The audio signals are alternating current (AC)signals. The ADC converts the audio signals to digital audio signalsthat are provided to the IC chip. In some cases, a capacitor can becoupled to the ADC to remove unwanted direct current (DC) signals whichmay be interfaced to the IC chip along with the received audio signals.The sensed voltage, as mentioned previously, is a DC voltage. Thus, thesame ADC cannot be used to transfer both the audio signals and thesensed voltage to the IC chip. Moreover, if the sensed voltage (which isa DC signal) is added to the audio signal (which is an AC signal), thenboth of the signals will lose their meaningful values.

To this end, systems and methods for power measurement in the electronicdevice are described herein. In an implementation, a sensor is placedacross a power source to measure power consumption of an IC chip in anelectronic device. A voltage drop across the sensor is sensed. Thesensed voltage is digitized using an ADC, which is also configured tocommunicate audio signals to the IC chip.

To reliably communicate both the sensed voltage and the audio signals,the sensed voltage is used to modulate a carrier signal. The frequencyof the carrier signal is selected such that there is minimalinterference of the modulated carrier signal with the frequency spectrumof the audio signals. In an implementation, the frequency of the carriersignal chosen for the modulation is greater than the audio frequencyrange.

The modulated carrier signal and the audio signals are combined togenerate a combined signal. Subsequently, the combined signal isdigitized. The digitized combined signal includes the digitizedcomponents of both the modulated carrier signal, as well as the audiosignal. From the digitized combined signal, the digitized modulatedcarrier signal components can be removed, say by filtering out thedigitized modulated carrier signal. In an implementation, a high passfilter can be used to block the digitized audio signals and allow thedigitized modulated carrier signal to pass. The filtered modulatedcarrier signal can be demodulated to provide an estimate of the sensedvoltage.

The method, thus, uses existing components for measuring the powerconsumed by the IC chip without requiring any additional number ofcomponents. Further, as the ADC is also used to interface the IC chip,additional pins of the IC chip are available to provide other functionsin the electronic device.

While aspects of described systems and methods for the power measurementcircuit in an electronic device can be implemented in any number ofdifferent environments, and/or configurations, the embodiments aredescribed in the context of the following exemplary systemarchitecture(s).

The descriptions and details of well-known devices and components areomitted for simplicity of the description. Although the devices areexplained as certain N-channel and P-channel devices, it can beappreciated that complementary devices are also possible in accordancewith the present subject matter. Accordingly, the logic level of controlsignals can either be active low or active high.

FIG. 1 illustrates an exemplary system 100 for power measurement, inaccordance with an embodiment of the present subject matter. The system100 includes an electronic device 102 coupled to a power source 104. Thepower source 104 provides power for the operation of the electronicdevice 102. Examples of the electronic device 102 include, but are notlimited to, mobile phones, PDAs, cameras, music players, video players,recorders, and televisions.

The electronic device 102 includes a sensing unit 106, one or moreinput/output (I/O) interface(s) 108, an ADC 110, and a controller 112.The sensing unit 106 senses power being consumed by the electronicdevice 102. In an implementation, the sensing unit 106 senses voltagedrop across a sensor coupled to the power source 104. In anotherimplementation, the sensing unit 106 is configured to modulate a carriersignal based on the sensed voltage to generate a modulated carriersignal.

The I/O interface(s) 108 interfaces the electronic device 102 with auser or other external devices. The I/O interface(s) 108 may include avariety of software and hardware interfaces, for example, interfaces forperipheral device(s) such as a keyboard, a microphone, a key-pad, adisplay screen, a mouse, an external memory, and a printer. For example,a microphone interfaces audio signals from a user to a mobile phone byusing an ADC, such as the ADC 110.

The ADC 110 converts analog signals to digital signals. The ADC 110 canreceive analog signals from the sensing unit 106 as well as from the I/Ointerface(s) 108. On receiving the analog signals, the ADC 110 convertsthe analog signals to digital signals and provides the digital signalsto the controller 112. The ADC 110 can be of different resolutions, forexample, 8 bits, 16 bits, and 32 bits. To implement the ADC 110, ADCshaving different dynamic range may be used based on the frequency rangeof the signals being received by the ADC 110. A dynamic range of an ADCindicates the frequency range of input signals that can be reliablyconverted to digital signals. For example, for audio signals, the ADC110 should reliably convert signals having a frequency in the range ofabout 20 Hz to 20 KHz.

The controller 112 is configured to perform various functions of theelectronic device 102. Among other things, the controller 112 managesthe power requirements of the electronic device 102. The controller 112includes a signal processing unit 114, a power management unit 116, andother units 118. The signal processing unit 114 filters a digitizedmodulated carrier signal from digital signals received by the controller112. Further, the signal processing unit 114 demodulates the digitizedmodulated carrier signal to generate an output signal that is based onthe sensed voltage. In an implementation, the digital signals can bereceived from the ADC 110.

The power management unit 116 manages the power requirements of theelectronic device 102 based on the output signal that is based on thesensed voltage. In an implementation, the power management unit 116controls power supply to certain components of the electronic device 102based on the output signal. For example, in a mobile phone, the powermanagement unit 116 can adaptively control LCD backlight display basedon the output signal which provides a measure of the power beingconsumed by the mobile phone.

In an implementation, the power management unit 116 estimates the powerrequirements of the electronic device 102. Based on a difference ofrequired power and measured power, the power management unit 116 canconfigure various components of the electronic device 102 to operate atan optimal operating point, for proper functioning of the electronicdevice 102.

It is to be noted that the controller 112 may be implemented in a singleIC chip, or in a combination of IC chips. Further, the components of theelectronic device 102 can be integrated together to form asystem-on-a-chip.

In operation, signals, for example, audio signals, from the I/Ointerface(s) 108 are sent to the ADC 110. Also, the sensing unit 106senses the voltage across the power source 104 using a sensor. Once thesensed voltage is obtained, the sensing unit 106 generates the carriersignal and then modulates the carrier signal based on the sensedvoltage. In one implementation, the sensing unit 106 performs amplitudemodulation of the carrier signal based on the sensed voltage.

The frequency of the carrier signal is chosen such that the carriersignal does not interfere with the frequency of the audio signalsreceived by the ADC 110. In one implementation, the frequency of thecarrier signal is selected by the sensing unit 106. The modulatedcarrier signal is sent to the ADC 110. The ADC 110 digitizes acombination of the audio signals received from the I/O interface(s) 108and the modulated carrier signal received from the sensing unit 106 andgenerates a digitized combined signal. The digitized combined signalgenerated by the ADC 110 is passed to the controller 112.

The signal processing unit 114 of the controller 112 separates thedigitized combined signal into the digitized modulated carrier signaland the digitized audio signals. In an implementation, the signalprocessing unit 114 filters the digitized modulated carrier signal fromthe digitized combined signal. The signal processing unit 114demodulates the digitized modulated carrier signal to generate an outputsignal.

It would be noted that the output signal would be based on the modulatedcarrier signal, and in turn also based on the sensed voltage. The outputsignal thus provides an estimate of the power consumed by the electronicdevice 102. Further, the output signal is provided to the powermanagement unit 116, which manages the power requirements of theelectronic device 102. In an implementation, the power management unit116 can include a control loop having a reference input of the powerrequirements of the electronic device 102. Based on a comparison of theoutput signal with the reference input, the power management unit 116can adjust various components of the electronic device 102 toappropriate operating points such that the reference input is matched.

The digitized audio signals filtered by the signal processing unit 114,on the other hand, are passed on to the other units 118 for furtherprocessing. For example, in a mobile phone, the audio signals can becommunicated from one mobile phone to another using the other units 118.

FIG. 2 illustrates the electronic device 102, in accordance with anembodiment of the present subject matter. The components of theelectronic device 102 may be implemented using multiple circuits workingin cooperation, or may be integrated together to form a singlesystem-on-a-chip (SOC). The embodiment illustrated in the followingparagraphs, is for the purpose of illustration only. A plurality ofother components can also be included to implement multiplefunctionalities within the electronic device 102.

As indicated previously, the electronic device 102 includes the sensingunit 106, the I/O interface(s) 108, the ADC 110, and the controller 112.The sensing unit 106 includes a sensor 202 for sensing the powerconsumed by the electronic device 102 from the power supply 104. Thevoltage drop across the sensor, hereinafter referred to as sensedvoltage, is sensed. In an implementation, the sensor 202 can be aresistor commonly known in the art, across which a voltage drop issensed. However, other implementations of the sensor 202, for example, alow dropout voltage regulator, are also within the scope of the presentsubject matter.

The sensing unit 106 also includes a modulation unit 204 for modulatinga carrier signal based on the sensed voltage. In an implementation, themodulation unit 204 generates the carrier signal. The carrier signal canbe generated by using circuits commonly known in the art, for example, aWien bridge oscillator.

The I/O interface(s) 108 includes an audio interface 206 and otherinterface(s) 208. The audio interface 206 receives audio signals fromexternal devices or a user, and sends them to the controller 112. In animplementation, the audio interface 206 passes the audio signals throughthe ADC 110. The audio interface 206 can include a microphone forreceiving the audio signals.

The other interface(s) 208 receive other inputs, for example, keystrokes, mouse, video signals, etc., from the user or external devices.The other interface(s) 208 may include, but are not limited to, displayscreens, touch pads, key pads, key boards, and mouse.

Further, the signal processing unit 114 includes a filtering unit 210and a demodulation unit 212. The filtering unit 210 filters thedigitized modulated carrier signal from the digitized combined signalreceived from the ADC 110. In one implementation, the filtering unit 210can be implemented using a high pass filter for filtering the digitizedmodulated carrier signal. However, any other implementation of thefiltering unit 210 for filtering the digitized modulated carrier signalis also possible. The filtering unit 210 may be implemented as hardwareusing components such as resistors, capacitors, and inductors, or assoftware in an IC. In one implementation, the filtering unit 210 can beconfigured to separately provide the digitized modulated carrier signaland the digitized audio signal.

Once obtained, the demodulation unit 212 demodulates the digitizedmodulated carrier signal to generate an output signal. In animplementation, the demodulation unit 212 can be an envelope detectorfor demodulating the digitized modulated carrier signal. However, otherimplementations of the demodulation unit 212 based on the type ofmodulation scheme used are also within the scope of the invention. Asindicated previously, the output signal is based on the modulatedcarrier signal, which in turn is based on the sensed voltage. The outputsignal can, therefore, be used to provide an estimate of the powerconsumed by the electronic device 102.

In operation, the voltage across the sensor 202 is sensed to determinethe power drawn from the power supply 104. The modulation unit 204generates a carrier signal. The frequency of the carrier signal is soselected so that it causes minimal or no interference with the audiosignals, such as the audio signals received by the audio interface 206.The modulation unit 204 modulates the carrier signal based on the sensedvoltage. In an implementation, the modulation unit 204 performsamplitude modulation of the carrier signal. In another implementation,the modulation unit 204 amplifies the sensed voltage before modulatingthe carrier signal. The modulation unit 204 sends the modulated carriersignal to the ADC 110.

The ADC 110 receives the modulated carrier signal from the modulationunit 204, and the audio signals from the audio interface 206. The ADC110 digitizes the modulated carrier signal and the audio signals. Themodulated carrier signal and the audio signals are combined together andthen digitized using the ADC 110. In an implementation, the modulatedcarrier signal and the audio signals are added together using an addercircuit. The ADC 110 sends the digitized combined signal to the signalprocessing unit 114.

The filtering unit 210 filters the digitized modulated carrier signalfrom the digitized combined signal. The digitized modulated carriersignal is then passed to the demodulation unit 212. The demodulationunit 212 demodulates the digitized modulated carrier signal to generatethe output signal. The output signal is based on the sensed voltagewhich was measured across the sensor 202. As indicated previously, thesensed voltage provides an estimate of the power consumed by theelectronic device 102. The output signal is sent to the power managementunit 116 for power management operations in the electronic device 102,as described earlier.

These and other aspects can be better understood in conjunction with thesignal graphs, as shown in FIG. 3. It is to be noted that the graphsrepresent digital signals with the horizontal axis representing time,while the vertical axis representing the magnitude of the signal.

FIG. 3 (a) illustrates a graph of the digitized combined signal, asgenerated by the ADC 110. The digitized combined signal, as mentionedpreviously, is a mixture of the audio signals received from the audiointerface 206 and the modulated carrier signal from the modulation unit204. The ADC 110 provides the digitized combined signal to thecontroller 112.

The filtering unit 210 receives the digitized combined signal andfilters out the digitized modulated carrier signal, as shown in FIG. 3(b). The digitized modulated carrier signal shown in FIG. 3 (b) is anamplitude modulated carrier signal. The amplitude of the digitizedmodulated carrier signal is based on the sensed voltage.

Once the digitized modulated carrier signal is obtained, it is passed tothe demodulation unit 212. The demodulation unit 212 demodulates thedigitized modulated carrier signal to generate the output signal, whichis represented in FIG. 3 (c), as per one implementation of the presentsubject matter. In such an implementation, when the modulated carriersignal is amplitude modulated, the demodulation unit 212 detects theenvelope of the digitized modulated carrier signal and generates theoutput signal based on the detected envelope. The demodulation unit 212then provides a measure of the output signal, represented in FIG. 3 (d).This output signal can be provided to the power management unit 116 forits operation. It would be appreciated that the signal graphs have beenshown for illustration purposes only, and the scope of the presentsubject matter should not be construed as limited to these graphs only.

FIG. 4 illustrates an exemplary circuit of the sensing unit 106 forgenerating the modulated carrier signal, in accordance with anembodiment of the present subject matter. The sensor 202 is illustratedas a resistor. However, any other implementation of the sensor 202, suchas a voltage regulator, is also possible. The modulation unit 204 isconfigured to perform amplitude modulation of the sensed voltage acrossthe sensor 202. In an implementation, the modulation unit 204 includes acarrier signal generator 402, a pre-processing unit 404, and a modulator406.

The carrier signal generator 402 is configured to generate a carriersignal that is modulated based on the sensed voltage. In animplementation, the frequency of the carrier signal generated by thecarrier signal generator 402 can be above the audio frequency range (20Hz to 20 KHz). In a one embodiment, the frequency of the carrier signalgenerated is about 20 KHz. The carrier signal generator 402 can beimplemented using standard components such as transistors, operationalamplifiers, capacitors, and resistors, known in the art. Forillustration purposes, the carrier signal generator 402 shown is a Wienbridge oscillator circuit.

The pre-processing unit 404 amplifies the sensed voltage for effectivemeasurement. In an implementation, the pre-processing unit 404 includesan operational amplifier and one or more resistors. The pre-processingunit 404 and the carrier signal generator 402 are coupled to themodulator 406. The modulator 406 modulates the carrier signal from thecarrier signal generator 402 based on the sensed voltage received fromthe pre-processing unit 404. In an implementation, the modulator 406performs amplitude modulation of the carrier signal based on the sensedvoltage. The modulator 406 may further include an amplitude modulator(A.M) 408 for transmitting the amplitude modulated carrier signal.

In operation, the sensor 202 senses voltage across the power source 104to generate the sensed voltage. The pre-processing unit 404 amplifiesthe sensed voltage so that the carrier signal generated by the carriersignal generator 402 can be effectively modulated. The modulator 406receives the carrier signal from the carrier signal generator 402, andthe sensed voltage from the pre-processing unit 404. The AM 408transmits the modulated carrier signal to the ADC 110 for furtherprocessing, as described earlier.

FIG. 5 illustrates an exemplary method 500 for power measurement in anelectronic device, in accordance with an embodiment of the presentsubject matter. The power electronic device is configured to receiveaudio signals through an ADC.

The order in which the method is described is not intended to beconstrued as a limitation, and any number of the described method blockscan be combined in any order to implement the method, or an alternatemethod. Additionally, individual blocks may be deleted from the methodwithout departing from the spirit and scope of the subject matterdescribed herein. Furthermore, the method can be implemented in anysuitable hardware, software, firmware, or combination thereof.

At block 502, voltage across a power source is sensed. The sensing canbe performed by using a sensor placed across the power source, inparallel to the components of the electronic device being driven by thepower source. For example, the sensor 202 is placed across the powersource 104 to sense the power consumed by the electronic device 102.

At block 504, a carrier signal is modulated based on the sensed voltage.The carrier signal can be generated, and then modulated based on thesensed voltage. In one implementation, the sensed voltage can be firstamplified and then used to modulate the carrier signal. The frequency ofthe carrier signal is chosen such that the audio signals and themodulated carrier signal do not interfere with each other. In animplementation, the frequency of the carrier signal selected is greaterthan the audio frequency range (20 Hz to 20 KHz). For example, themodulation unit 204 generates the carrier signal. Once generated, themodulation unit 204 modulates the carrier signal based on the sensedvoltage obtained from sensor 202. In an implementation the modulationunit 204 performs amplitude modulation of the carrier signal based onthe sensed voltage.

At block 506, the modulated carrier signal is combined with the audiosignals received by the electronic device. The modulated carrier signaland the audio signals can be added together to generate a combinedsignal. In an implementation, the audio signals received by the audiointerface 206 and the modulated carrier signal from the modulation unit204 are combined together using an adder circuit.

At block 508, the combined signal including the audio signals and themodulated carrier signal is converted to a combined digital signal. Thecombined digital signal includes the components of the audio signals andthe modulated carrier signal. It is to be noted that a single ADC can beused to convert the combined signal to the combined digital signal. Forexample, the ADC 110 digitizes the combined signal to generate thedigitized combined signal.

At block 510, the modulated carrier signal is filtered from the combineddigital signal. As the frequency of the carrier signal chosen isdifferent from that of the audio signals, the filtering of the modulatedcarrier signal can be easily performed. In an implementation, a highpass filter can be used to filter the modulated carrier signal from thecombined digital signal. For example, the filtering unit 210 filters outthe modulated carrier signal from the digitized combined signal.

At block 512, the modulated carrier signal is demodulated to generate anoutput signal. The output signal is based on the sensed voltage used tomodulate the carrier signal. For example, the demodulation unit 212demodulates the digitized modulated carrier signal to generate theoutput signal. In an implementation, when the carrier signal isamplitude modulated based on the sensed voltage, the demodulationincludes detecting an envelope of the digitized modulated carrier signalto generate the output signal.

At block 514, the power requirements of the electronic device aremanaged based on the output signal. For example, the demodulation unit212 passes the output signal to the power management unit 116 forfurther operations, such as managing LCD backlight display and meetingpower requirements of the electronic device based on the output signal.

Although embodiments for measurement of have been described in languagespecific to structural features and/or methods, it is to be understoodthat the invention is not necessarily limited to the specific featuresor methods described. Rather, the specific features and methods aredisclosed as exemplary embodiments for testing of the shadow logic.

We claim:
 1. A method for measuring power consumed by a mobile wirelesscommunications device, the method comprising: modulating a carriersignal based on a sensed voltage across a power source; combining themodulated carrier signal with at least one wireless communication signalreceived by the mobile wireless communications device; converting thecombined signal to a digital combined signal; and demodulating adigitized modulated carrier signal from the digital combined signal toestimate the power consumed by the mobile wireless communicationsdevice.
 2. The method of claim 1 further comprising generating an outputsignal based on the digitized modulated carrier signal for measuring thepower consumed by the electronic device.
 3. The method of claim 1wherein modulating comprises generating the carrier signal with afrequency greater than a frequency range associated with the at leastone wireless communication signal.
 4. The method of claim 1 whereinmodulating comprises sensing the sensed voltage corresponding to thepower consumed from the power source.
 5. The method of claim 1 whereindemodulating comprises generating an output signal from the digitizedmodulated carrier signal based on the sensed voltage.
 6. The method ofclaim 1 wherein demodulating comprises detecting an envelope of thedigitized modulated carrier signal to generate the output signal.
 7. Amobile wireless communications device comprising: a modulator configuredto modulate a carrier signal based on a sensed voltage across a powersource; an analog-to-digital converter (ADC) configured to convert themodulated carrier signal and at least one wireless communication signalreceived by the mobile wireless communications device into a digitalcombined signal; and a demodulator configured to demodulate a digitizedmodulated carrier signal from the digital combined signal to estimatethe power consumed by the mobile wireless communications device.
 8. Themobile wireless communications device of claim 7 wherein saiddemodulator is configured to generate an output signal based on thedigitized modulated carrier signal for measuring the power consumed bythe electronic device.
 9. The mobile wireless communications device ofclaim 7 wherein said modulator is configured to generate the carriersignal with a frequency greater than a frequency range associated withthe at least one wireless communication signal.
 10. The mobile wirelesscommunications device of claim 7 wherein said modulator is configured tomodulate the carrier signal corresponding to power consumed from thepower source.
 11. The mobile wireless communications device of claim 7wherein said demodulator is configured to generate an output signal fromthe digitized modulated carrier signal based on the sensed voltage. 12.The mobile wireless communications device of claim 7 wherein saidmodulator is configured to detect an envelope of the digitized modulatedcarrier signal to generate the output signal.
 13. A non-transitorycomputer-readable medium having computer-executable instructions forcausing a mobile wireless communications device to perform stepscomprising: modulating a carrier signal based on a sensed voltage acrossa power source; combining the modulated carrier signal with at least onewireless communication signal received by the mobile wirelesscommunications device; converting the combined signal to a digitalcombined signal; and demodulating a digitized modulated carrier signalfrom the digital combined signal to estimate the power consumed by themobile wireless communications device.
 14. The non-transitorycomputer-readable medium of claim 13 further having computer-executableinstructions for causing the mobile wireless electronic device togenerate an output signal based on the digitized modulated carriersignal for measuring the power consumed by the electronic device. 15.The non-transitory computer-readable medium of claim 13 whereinmodulating comprises generating the carrier signal with a frequencygreater than a frequency range associated with the at least one wirelesscommunication signal.
 16. The non-transitory computer-readable medium ofclaim 13 wherein modulating comprises sensing the sensed voltagecorresponding to the power consumed from the power source.
 17. Thenon-transitory computer-readable medium of claim 13 wherein demodulatingcomprises generating an output signal from the digitized modulatedcarrier signal based on the sensed voltage.
 18. The non-transitorycomputer-readable medium of claim 13 wherein demodulating comprisesdetecting an envelope of the digitized modulated carrier signal togenerate the output signal.